2020, Vol. 5, No. 4

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Cellulose Nanocomposites:Fabrication and Biomedical Applications
Blessy Joseph, Sagarika V K, Chinnu Sabu, Nandakumar Kalarikkal, Sabu Thomas
2020, 5(4): 231-247. doi: 10.1016/j.jobab.2020.10.001
Cellulose is a linear biopolymer which is composed of nanofibrils, thus having a large surface area. This low-cost, low-density, high-specific-surface-area, easily processable polymer is found in nature in the form of plants, bacteria and tunicates. Cellulose has outstanding characteristics including low cytotoxicity, biocompatibility, good mechanical properties, high chemical stability, and cost effectiveness which make them suitable candidates for biomedical applications. The manipulation of cellulose at nanoscale resulted in nanocellulose having exceptional physicochemical properties. Therefore, cellulose nanocomposite is a fascinating area of research which has applications in biomedical fields like wound healing, bone tissue engineering, three dimensional printing, drug carriers, medical implants etc. This review is mainly focused on the developments in the generation of cellulose nanocomposites and their potential applications in the biomedical field.
A review on conversion of crayfish-shell derivatives to functional materials and their environmental applications
Shuo Chen, Shunfeng Jiang, Hong Jiang
2020, 5(4): 238-247. doi: 10.1016/j.jobab.2020.10.002
As a new research focus in the field of biological resources, crayfish shells have great potential for development and utilization. In this review, the typical methods and research progress of separating the primary components such as chitosan, protein, and astaxanthin from crayfish shells and converting crayfish shells into functional carbon-based materials are introduced in detail. Then, the application of crayfish shell and typically modified crayfish-shell biochar in adsorption, antibacterial, electrochemical, etc. is reviewed. Finally, the future research outlook is proposed. This review can provide some perspectives on the development of the application of crayfish shells and crayfish-shell derivatives.
Development and Characterization of Food Packaging Bioplastic Film from Cocoa Pod Husk Cellulose Incorporated with Sugarcane Bagasse Fibre
Siti Nuurul Huda Mohammad Azmin, Najah Aliah Binti Mohd Hayat, Mohd Shukri Mat Nor
2020, 5(4): 259-266. doi: 10.1016/j.jobab.2020.10.003
Agricultural wastes, including cocoa pod husk (waste from the chocolate industry) and sugarcane bagasse (waste from the sugar industry), are increasing day by day. The development of food packaging biofilms from these two wastes could be beneficial to the environment and human. Therefore, this study was conducted to develop biodegradable plastic films by using cocoa pod husk and sugarcane bagasse. Cellulose and fibre were extracted from cocoa pod husk and sugarcane bagasse, respectively. The developed bioplastic films were divided into several concentration ratios of cellulose and fibre which are 100:0 (100% cellulose), 75:25 (cellulose:fibre), 50:50 (cellulose:fibre), 25:75 (cellulose:fibre), and 0:100 (100% fibre). The physicochemical properties for all bioplastic concentration ratios were determined in terms of sensory evaluation, drying time, moisture content, water absorption and water vapor permeability. From the observation and analysis of the physicochemical properties of bioplastic, we found that the most suitable bioplastic film for food packaging goes to the combination of 75% cellulose and 25% fibre bioplastic, as it demonstrated the lowest water absorption percentage and water vapor permeability.
Mechanical behaviour of wood compressed in radial direction:Part II. Influence of temperature and moisture content
Chen Huang, Yinghei Chui, Meng Gong, Felisa Chana
2020, 5(4): 266-275. doi: 10.1016/j.jobab.2020.10.005
This study investigated the influence of pressing temperature and moisture content on the mechanical properties of wood compressed in radial direction. Jack pine (Pinus banksiana) and balsam poplar (Populus balsamifera) specimens were tested under a combination of pressing temperature (20℃, 55℃, 90℃, and 125℃) and wood moisture content (2%, 7%, 12%, and 17%). The yield stress (σy) and modulus of elasticity (MOE) of the specimens were determined from the stress-strain response. It was found that an increase in either pressing temperature or moisture content of wood generally caused a decrease in the mechanical properties for both species. The t-test results revealed that jack pine specimens are more sensitive to changes in pressing temperature and wood moisture content than balsam poplar. For jack pine specimens, at any of the pressing temperatures, the moisture content of 12% was found to be a crucial level to start a significant decrease in σy and MOE, while at any of the moisture content, a change in temperature from 55℃ to 90℃ exhibited a significant change in σy and MOE. The regression models developed can be used to predict σy and MOE as a function of temperature and moisture content.
Production of Jet Fuel Intermediates from Biomass Platform Compounds via Aldol Condensation Reaction Over Iron-Modified MCM-41 Lewis Acid Zeolite
Mingxue Su, Wenzhi Li, Qiaozhi Ma, Bowen Zhu
2020, 5(4): 267-276. doi: 10.1016/j.jobab.2020.10.004
Liquid fuel intermediates could be produced via aldol condensation reaction between furfural or 5-hydroxymethylfurfural (HMF) and acetone. It was found that iron-modified MCM-41 zeolite can be an effective Lewis acid catalyst for C-C bond formation via aldol condensation of furfural or HMF with acetone. The 4-(2-furyl)-3-buten-2-one and 1, 5-di-2-furanyl-1, 4-pentadien-3-one (FAc and F2Ac), or 1, 5-di-2-furanyl-1, 4-pentadien-3-one and 1, 5-bis[(5-hydroxlmethyl)-2-furanyl]-1, 4-pentadien-3-one (HAc and H2Ac), as two main condensation products of furfural with acetone or HMF with acetone, were observed. After 24 h at 160℃, 86.9% conversion of furfural with 60.0% yield of the FAc as well as 7.5% yield of the F2Ac and 88.9% conversion of the HMF with 41.1% yield of the HAc as well as 3.5% yield of the H2Ac were achieved. Although furfural or HMF conversion was almost same after 24 h at 160℃, iron-modified MCM-41 zeolite catalyst displayed an enhanced selectivity to condensation products of furfural with acetone. In addition, catalysts showed an improved selectivity to the F2Ac and H2Ac at higher reaction temperature. The reusability and regeneration studies showed that iron-modified MCM-41 zeolite catalyst could not be reused directly, but could be regenerated by calcination in air, and the catalytic performance of regenerated catalyst was acceptable.
Extraction of allelochemicals from poplar alkaline peroxide mechanical pulping effluents and their allelopathic effects on Microcystis aeruginosa
Yanyan Wang, Mengxing Zhao, Tingzhi Liu
2020, 5(4): 276-282. doi: 10.1016/j.jobab.2020.10.006
In this study, allelochemicals were extracted from pulping effluents rather than from the raw material of plants. Herein, five organic solvents (ethyl acetate (EAC), methyl tert-butyl ether (MTBE), dichloromethane (DCM), carbon tetrachloride (CTC), and petroleum (PE)) were applied to separately extracting the allelochemicals from alkaline peroxide mechanical pulp (APMP) effluents. The results from the algal density, inhibition ratio, and optical density of 446 nm (OD446nm) concluded that the extractives from the APMP effluents can act as effective allelochemicals and showed noticeable allelopathic inhibition effects on Microcystis aeruginosa growth. The results indicated that organic solvent extraction could be a practical approach to isolate the allelochemicals from the APMP effluents, which would broaden the potential application of the APMP effluents in the production of antimicrobial agents and other value-added materials.
Optimization and kinetics of glucose production via enzymatic hydrolysis of mixed peels
Ude Michael U., Oluka Ike, Eze Paul C.
2020, 5(4): 283-290. doi: 10.1016/j.jobab.2020.10.007
The optimization and kinetics of glucose production via enzymatic hydrolysis of mixed peels were carried out. The substrate was characterized using proximate analysis and hydrolysis. The process was optimized using response surface methodology while the kinetics of the hydrolysis was studied using Michealis-menten model. The results obtained showed that the mixed peels have high hemicellulose content, hydrolysable carbohydrate and cellulose. The optimum conditions for glucose yield of 79% by enzymatic hydrolysis are temperature of 36℃, time of five days, pH of 4.55 and enzyme dosage of 0.428 g/50mL. Enzymatic hydrolysis obeyed Michealis-Menten kinetic model with spontaneous and feasible reactions. Therefore, the results have proved that mixed peels (cassava and potato peels) is a good substrate for glucose production and study of other waste peels as feed-stock is recommended.
Esterification of Levulinic Acid into n-Butyl Levulinate Catalyzed by Sulfonic Acid-Functionalized Lignin-Montmorillonite Complex
Wenguang Zhao, Hui Ding, Jie Zhu, Xianxiang Liu, Qiong Xu, Dulin Yin
2020, 5(4): 303-311. doi: 10.1016/j.jobab.2020.10.008
In this study, sulfonic acid-functionalized lignin-montmorillonite complex (LMT-SO3H) was prepared and employed as an efficient heterogeneous catalyst for the esterification of levulinic acid (LA) into n-butyl levulinate (BL). An intermediate pseudo-butyl levulinate (p-BL) was determined by distilled water treatment and nuclear magnetic resonance (NMR) analysis, and a possible mechanism for the esterification of LA is proposed. The effects of various process parameters were studied and the results showed that the LMT-SO3H catalyst had the excellent catalytic performance for esterification of the LA. Under optimum reaction conditions, the yield of BL was 99.3% and the conversion of LA was 99.8%. The LMT-SO3H catalyst exhibited strong acidic sites and high stability even after seven cycles of usage. Furthermore, esterification of the LA with various alcohols over the LMT-SO3H was further investigated.